Problem with the multiple curriencies.

Ok, starting from the beginning i just install the plugin woocommerce multilingual. I set three currency -default Polish Zloty, Euro and British pound in my shop in currency switcher option – for test, and everything was great but when i delete this currency i got something like this () () in the currency order field. When i add new currency again i have got () () euro, british pound, what is the “()” and how i can delete this or reset to default value? hmm.. and i can’t choose my oryginal currency polish zl from the currency form too. I do not know what is happened.

http://www.nowy.korbik.com.pl/wp-content/uploads/2015/01/what-is-this.png

This situation occurs when I use function “Drag the currencies to change their order.” When I move the currency (drag and drop), after a few seconds I get () instead of currency. What’s happened, where i can reset this empty currencies -> () () () and where is my default currency Polish Zloty PLN?

http://www.nowy.korbik.com.pl/wp-content/uploads/2015/01/what-is-this-2.png

https://wordpress.org/plugins/woocommerce-multilingual/